I think that dmg's comments about MK' voice are correct. Analysing the whole thing with a clear mind after the concert, he saw that MK, unfortunately, was on his lowest point as a singer and guitar player.
For a man who did SO MUCH, it's was sad when I looked at him singing and playing on his last tour. And it was brave as well. I think that he expected to be in a better shape when the tour started and, even with all his problems, he did te whole tour.
There was some very good moments during the tour.
He gave all playing Speedway.
However, I would never imagine that he would need help to play the R&J intro.
As I said: Sad, but brave.
Talking about hiccups, he did it on Watch Me Gone.
It is ON THE RECORD.
So, try to imagine how hard was to record ODR.
Ah, my favorite MK's era as a singer was in 2011/2012 when he tried (an sung very well) Bonaparte in D and BIA in Am.
I am not a fan of high pitches. However, he did a great job.